Dark matter detection with hard X-ray telescopes
Abstract
We analyse the impact of future hard X-ray observations on the search for indirect signatures of particle dark matter in large extragalactic systems such as nearby clusters or groups of galaxies. We argue that the hard X-ray energy band falls squarely at the peak of the inverse-Compton emission from electrons and positrons produced by dark matter annihilation or decay for a large class of dark matter models. Specifically, the most promising are low-mass models with a hard electron-positron annihilation final state spectrum and intermediate-mass models with a soft electron-positron spectrum. We find that constraints on dark matter models similar to the current constraints from the Fermi Gamma-ray Space Telescope will be close to the sensitivity limit of the near-term hard X-ray telescopes Nuclear Spectroscopic Telescope Array (NuSTAR) and Astro-H for relatively long observations. An instrument like the Wide Field Imager proposed for Advanced Telescope for High ENergy Astrophysics (ATHENA) would instead give a significant gain in sensitivity to dark matter if placed in a low background orbit similar to NuSTAR's; however, given the higher expected background level for ATHENA's proposed orbit at L2, its sensitivity will be similar to that of NuSTAR.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- April 2012
- DOI:
- 10.1111/j.1365-2966.2011.20382.x
- arXiv:
- arXiv:1108.1407
- Bibcode:
- 2012MNRAS.421.1215J
- Keywords:
-
- acceleration of particles;
- radiation mechanisms: non-thermal;
- galaxies: clusters: general;
- dark matter;
- X-rays: galaxies: clusters;
- Astrophysics - High Energy Astrophysical Phenomena;
- Astrophysics - Cosmology and Nongalactic Astrophysics;
- High Energy Physics - Phenomenology
- E-Print:
- 18 pages, 3 figures, accepted to MNRAS, updated with predictions for ATHENA and some additional discussion of systematics